Improvement in upright piano actions



Rm LL ia FF iii right M15 Paiented March 18 AM. FHOTO-UT/IOGRAPHIC caN.X(osaomvs& PROCESS) UNITED STATES PATENT OFFICE.

RUDOLPH KRETER, OF NEW YORK, N. Y., IXSSIGNOR TO DAVID DECKER AND JOHNJ. DECKER, OF SAME PLACE.

IMPROVEMENT lN UPRIGHT PIANO ACTIONS.

Specification forming part of Letters Patent No. 131005, datedMarch 18,1873.

To all whom it may concern:

Be it known that I, RUDOLPH Kan'rna, of the city, county, and State ofNew York, have invented a new and useful Improvement in Piano-ForteActions; and 1 do hereby declare that the following is a full, clear,and exact description of the same, reference being had to theaccompanying drawing forming part of this specification, and in which-Figure 1 represents a vertical transverse section of a piano-forteaction having my improvement applied; Fig. 2, a similar view, sllOWingthe action thrown back; and Fig. 3, a view of the action in part fromthe front of the instrument.

Similar letters of reference indicate corresponding parts.

This invention relates to piano-fortes having an upright action; andconsists in a novel application or attachment of a spiral spring, whichthrows the hammer back, whereby a lively action is obtained for thehammer and the usual strap for completing the back-throw of it isdispensed with, and a back-throw of the hammer, similar to thatdependent upon gravity in horizontal action, is eifected. The inventionalso consists in a suspension about a common center of the hammer-rail,rest-rail, and regulating-rail, with accompanying portions of theaction, whereby the whole may be turned back or away from the strings toprovide for adjustment and repair without removal of the action from thecase of the instrument. The invention likewise consists in a certaindivided and pivoted construction of the standards which support theaction to facilitate or render more perfect the provision just named.

A in the accompanying drawing represents the hammer-rail of an uprightpiano-forte action; B, the hammer-butt; 0, its knuckle; D, its shank;and E its head. F is the hammerrest rail; G, the backcheck of the action5 H, the regulating-rail, provided with a let-off or regulating-screw,b; and I the jack. J is one of the playing keys; and K. the connectionor action-lift thereof, the same being jointed at c to the base-piece ofthe jack. L is the keyframe, and M N one of the standards by which theaction is carried. 0 is the spring for controlling the action of thehammer. This spring,

which is a light spiral one, and is connected at its one end to anupright or wire, d, attached to the butt B or hammenrail A, is connected at its opposite or free end to the knuckle O of the hammer in afixed or positive manner by a cord, wire, or strap-like 6X- tension ofit arranged to lap around a curved portion, so as always to work at thesame leverage on the knuckle of the hammer in close proximity to thefulcrum or center of motion of the latter and without change in theeffect of the spring by variation in the angle of its pull.

By this application or attachment of the spring a livelyaction isobtained for the hammer, and the usual strap for completing theback-throw of it is dispensed with, and the hammer is let down orreturned to its rest as gently as in horizontal piano-forte actions, inwhich the hammer is returned or thrown back by gravity.

The standards, by which the action is carried, are each made up of twoseparate pieces, M N, the one, M, of which is fastened to the key-frameL and carries the lower rail P. The other piece, D, is pivoted to thepiece M, so as to be capable of turning on a center, 9, which iscoincident with the centerof the lower jackconnection in order that thepiece N, which carries the hammer-rail A, rest-rail G, andregulating-rail H, with accompanying parts of the action, may all beturned back together, as shown in Fig. 3, thereby affording the greatestfacility for getting at the action, strings, and other parts, to elfectadjustment or repair without removing the action from the case of theinstrument. Attached to the piece M is a guide or barbed turningfastening, j, that, when the piece N is thrown up or closed, passesthrough the latter and may be turned to hold it in its raised position.Any other suitable fastening, however, may be substituted.

XVhat is here claimed, and desired to be secured by Letters Patent, is

1. The combination of the spiral spring 0, the upright d, and theknuckle G of the hammer, when these parts are arranged in relation witheach other and the spring connected to the knuckle in close proximity toits center of motion, 6, and around the latter, so as to act one, M, ofwhich is fastened to the key-frame, and the other piece, N, whichcarries the action, is pivoted to the fast piece M so as to turn on acenter which is coincident with the center 0 of the lowerjack-connection, essentially as herein described.

RUDOLPH KRETER. Witnesses:

' FRED HAYNES,

FEED. TUSOH.

